U.S. patent number 11,035,238 [Application Number 16/787,710] was granted by the patent office on 2021-06-15 for airfoil including adhesively bonded shroud.
This patent grant is currently assigned to RAYTHEON TECHNOLOGIES CORPORATION. The grantee listed for this patent is United Technologies Corporation. Invention is credited to Jeremy L. Fox, Nicholas D. Stilin.
United States Patent |
11,035,238 |
Stilin , et al. |
June 15, 2021 |
Airfoil including adhesively bonded shroud
Abstract
An airfoil includes an airfoil body that extends between a
leading edge and a trailing edge, a suction side and a pressure
side, and a first end and a second end, a fitting located at one of
the first end or the second end, the fitting including a body
portion, a fillet portion, and a neck portion joining the body
portion and the neck portion, the neck portion including a shelf, a
fastener through the airfoil body, and a shroud having a
complementary shape to the shelf such that the shroud nests in the
shelf.
Inventors: |
Stilin; Nicholas D. (Higganum,
CT), Fox; Jeremy L. (New Britain, CT) |
Applicant: |
Name |
City |
State |
Country |
Type |
United Technologies Corporation |
Farmington |
CT |
US |
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Assignee: |
RAYTHEON TECHNOLOGIES
CORPORATION (Farmington, CT)
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Family
ID: |
71608815 |
Appl.
No.: |
16/787,710 |
Filed: |
February 11, 2020 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200232334 A1 |
Jul 23, 2020 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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13527036 |
Jun 19, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01D
5/225 (20130101); F01D 11/005 (20130101); F01D
5/141 (20130101); F01D 5/303 (20130101); F01D
5/147 (20130101); F01D 9/042 (20130101); F05D
2230/60 (20130101); F05D 2300/43 (20130101); F05D
2230/52 (20130101); F05D 2240/12 (20130101); F05D
2260/31 (20130101); F05D 2220/36 (20130101) |
Current International
Class: |
F01D
5/30 (20060101); F01D 5/22 (20060101); F01D
5/14 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Extended European Search Report for European Application No.
13807627.8 dated Sep. 14, 2015. cited by applicant .
International Preliminary Report on Patentability for PCT
Application No. PCT/US2013/043815 dated Dec. 31, 2014. cited by
applicant .
International Search Report for International Application No.
PCT/US2013/043815 dated Sep. 11, 2013. cited by applicant.
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Primary Examiner: Heinle; Courtney D
Assistant Examiner: Christensen; Danielle M.
Attorney, Agent or Firm: Carlson, Gaskey & Olds,
P.C.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This disclosure is a continuation-in-part of U.S. patent
application Ser. No. 13/527,036 filed Jun. 19, 2012.
Claims
What is claimed is:
1. An airfoil comprising: an airfoil body extending between a
leading edge and a trailing edge, a suction side and a pressure
side, and a first end and a second end; a fitting located at one of
the first end or the second end, the fitting including a body
portion, a fillet portion, and a neck portion joining the body
portion and the fillet portion, the neck portion including a shelf
and there being a slot that extends through the fillet portion, the
neck portion, and the body portion, the airfoil body extending in
the slot; a fastener through the body portion and the airfoil body;
and a shroud having a complementary shape to the shelf such that
the shroud nests in the shelf.
2. The airfoil as recited in claim 1, wherein the shroud comprises
a polymeric material.
3. The airfoil as recited in claim 1, wherein the fitting is
metallic and the shroud is polymeric.
4. The airfoil as recited in claim 1, further comprising a seal
member at a perimeter edge of the shroud.
5. The airfoil as recited in claim 4, wherein the perimeter edge
includes a groove that is complementary in shape to the seal
member.
6. The airfoil as recited in claim 5, wherein the groove has a
cross-sectional profile of a partial circle.
7. A turbine engine comprising a fan section including the airfoil
as recited in claim 1, a compressor section in communication with
the fan section, a combustor in fluid communication with the
compressor section, and a turbine section in fluid communication
with the combustor.
8. The airfoil as recited in claim 1, wherein the fillet portion
extends from the neck portion and opposite from the fillet portion
the body portion extend from the neck portion.
9. The airfoil as recited in claim 8, wherein the airfoil body
includes a though-hole from the suction side to the pressure side,
and the fastener is disposed through the through-hole.
Description
BACKGROUND
This disclosure relates to improvements in shrouded airfoils.
Airfoils, such as airfoils in gas turbine engines, may include a
shroud at an inner diameter, outer diameter or both. The airfoils
are circumferentially arranged such that inner diameter shrouds
bound an inner diameter of a gas path and outer diameter shrouds
bound an outer diameter of the gas path.
The airfoils are secured to static structures, such as cases, using
fittings at the inner and outer diameters. The fittings and shrouds
are integrally formed in a forging process from a suitable metallic
alloy or are integrally formed by machining from a single
monolithic piece of a suitable metallic alloy.
SUMMARY
An airfoil according to an example of the present disclosure
includes an airfoil body that extends between a leading edge and a
trailing edge, a suction side and a pressure side, and a first end
and a second end. A fitting is located at one of the first end or
the second end. The fitting includes a body portion, a fillet
portion, and a neck portion joining the body portion and the neck
portion. The neck portion includes a shelf, and here is a fastener
through the airfoil body. A shroud has a complementary shape to the
shelf such that the shroud nests in the shelf.
In a further embodiment of any of the foregoing embodiments, the
shroud comprises a polymeric material.
In a further embodiment of any of the foregoing embodiments, the
fitting is metallic and the shroud is polymeric.
The airfoil as recited in claim 1, further comprising a seal member
at a perimeter edge of the shroud.
In a further embodiment of any of the foregoing embodiments, the
perimeter edge includes a groove that is complementary in shape to
the seal member.
In a further embodiment of any of the foregoing embodiments, the
groove has a cross-sectional profile of a partial circle.
A gas turbine engine according to an example of the present
disclosure includes an airfoil as in of any of the foregoing
embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of the present disclosure will
become apparent to those skilled in the art from the following
detailed description. The drawings that accompany the detailed
description can be briefly described as follows.
FIG. 1 shows an example gas turbine engine.
FIG. 2 shows a perspective view of an airfoil of the gas turbine
engine of FIG. 1.
FIG. 3 shows an isolated view of a first, outer diameter fitting of
the airfoil of FIG. 2.
FIG. 4 shows an isolated view of a second, inner diameter fitting
of the airfoil of FIG. 2.
FIG. 5 shows an isolated view of the first, outer diameter fitting
and shroud of the airfoil of FIG. 2.
FIG. 6 shows an isolated view of the second, inner diameter fitting
and shroud of the airfoil of FIG. 2.
FIG. 7 shows a cross-section of a shroud adhesively bonded to a
fitting.
FIG. 8 shows an isolated view of a shroud of the airfoil of FIG.
2.
FIG. 9 shows another example shroud having a separate and distinct
shroud pieces.
FIG. 10 shows a sectioned, perspective view of a fitting and a
shroud that includes a seal member.
FIG. 11 shows a perspective view of a second, inner diameter
fitting, shroud and seal member.
FIG. 12 shows a perspective view of a first fitting, shroud and
seal member.
FIG. 13 shows a portion of a shroud having a slot receiving a seal
member.
FIG. 14 illustrates another example fitting and shroud.
DETAILED DESCRIPTION
FIG. 1 schematically illustrates a gas turbine engine 20. The gas
turbine engine 20 disclosed herein is a two-spool turbofan that
generally includes a fan section 22, a compressor section 24, a
combustor section 26 and a turbine section 28 that are arranged
along a central axis A. Although the illustrated example is a
turbofan gas turbine engine and the examples herein are described
with reference to an airfoil in the engine 20, it is to be
understood that this disclosure is not limited to gas turbine
engines or turbine engine airfoils. The teachings herein can be
applied to other types of shrouded airfoils and turbine engines,
including single- or three-spool architectures.
The fan section 22 of the gas turbine engine 20 includes a
plurality of rotatable blades 30 and a plurality of static,
structural exit guide vanes 32. As known, the vanes 32 are
circumferentially arranged around the central axis A between an
outer structure 34 and an inner structure 36, such as cases.
FIG. 2 shows an example of one of the vanes 32, which is considered
to be an airfoil. The vane 32 includes an airfoil body 40 that
extends between a leading edge 42 and the trailing edge 44, a
suction side 46 and a pressure side 48, and a first end 50 and a
second end 52. Relative to the central axis A, the first end 50 is
an outer diameter end of the vane 32 and the second end 52 is an
inner diameter end of the vane 32.
The vane 32 further includes a first fitting 54a located at the
first end 50 and a second fitting 54b located at the second end 52.
Each of the fittings 54a/54b is or includes a metallic material and
includes one or more mounting lugs 56 for securing the vane 32 to
the respective structures 34/36 in a known manner, such as by using
fasteners.
The vane 32 further includes a first shroud 58a that is adhesively
bonded to the first fitting 54a and a second shroud 58b that is
adhesively bonded to the second fitting 54b. Thus, in this example,
the vane 32 is shrouded at both the first end 50 and the second end
52. It is to be understood, however, that other types of airfoils
may be shrouded at only one end, and that the examples herein are
also applicable to such airfoils. As can be appreciated, use of the
shrouds 58a/58b that are separate and distinct pieces from the
airfoil body 40 and the respective fittings 54a/54b permits the
shrouds 58a/58b to be made of different material than either the
airfoil body 40 or the fittings 54a/54b.
FIGS. 3 and 4 show isolated views, respectively, of the first
fitting 54a and the second fitting 54b. In this example, each of
the fittings 54a/54b is a separate and distinct piece from the
airfoil body 40. In this regard, each of the fittings 54a/54b
includes a corresponding pocket 60 into which the airfoil body 40
is received. The airfoil body 40 can be adhesively bonded to the
respective fittings 54a/54b. In other examples, the fittings
54a/54b can be integral with the airfoil body 40.
FIGS. 5 and 6 show isolated views, respectively, of the shrouds
58a/58b adhesively bonded to the fittings 54a/54b. FIG. 7 shows a
cross-section through an interface between the second fitting 54b
and the second shroud 58b adhesively bonded to the second fitting
54b. It is to be understood that the interface between the first
fitting 54a and the first shroud 58a is similar to the interface
shown in FIG. 7. As shown, the second shroud 58a is adhesively
bonded to the second fitting 54b by an adhesive 70. In one example,
the adhesive 70 is an epoxy adhesive. In other examples, other
types of adhesives can be used that are suitable for the expected
operating temperature of the airfoil.
The second fitting 54b includes a flange F to which the second
shroud 58a is adhesively bonded. In this example, the flange F
includes a rabbet 54b'. The rabbet 54b', or ledge, supports the
adhesive 70 for bonding the second shroud 58b thereto. Thus, the
second shroud 58b is adhesively bonded to the rabbet 54b'. A method
of assembling the vane 32 therefore includes providing the vane 32
as described, and adhesively bonding the shrouds 58a/58b to the
fittings 54a/54b.
FIG. 8 shows an isolated view of the first shroud 58a. In this
example, the first shroud 58a includes a shroud body 72 that
extends between first and second broadsides 74a/74b, perimeter
edges 76, which are axially and circumferentially facing surfaces,
and interior edges 78 that define an elongated, arcuate opening 80
extending between the first and second broadsides 74a/74b. The
opening 80 is generally elongated in a direction parallel to the
central axis A of the gas turbine engine 20. The opening 80 also
has the arcuate shape, which corresponds to the arcuate shape of
the cross-section of the airfoil body 40.
The first shroud 58 also optionally includes a plurality of
additional openings 82 that correspond to the mounting lugs 56 on
the first fitting 54a. Depending on the geometry of the first
shroud 58a and location of the mounting lugs 56, other examples may
exclude the additional openings 82.
It is to be understood that the second shroud 58b has similar
features as the first shroud 58a with regard to including a shroud
body, first and second broadsides, perimeter edges and interior
edges that define an elongated, arcuate opening. As can be
appreciated, the contouring and size of the second shroud 58b may
differ and the elongated, arcuate opening of the second shroud 58b
may have a different geometry that corresponds to the cross-section
of the airfoil body 40 at the inner diameter. Also, the additional
optional openings may be positioned differently to align with the
mounting lugs 56 on the second fitting 54b.
In this example, the first shroud 58a is a monolithic piece. That
is, the first shroud 58a is a single piece of material that is free
of joints or seams. Thus, in the assembly of the vane 32, the
airfoil body 40 extends through the elongated, arcuate opening 80
and into the corresponding first fitting 54a (or second fitting 54b
for the elongated arcuate opening of the second shroud 58b).
FIG. 9 shows a modified example of a first shroud 158a. In this
disclosure, like reference numerals designate like elements where
appropriate and reference numerals with the addition of one-hundred
or multiples thereof designate modified elements that are
understood to incorporate the same features and benefits of the
corresponding elements. In this example, the first shroud 158a
includes a plurality of separate and distinct pieces 190a/190b.
Each of the pieces 190a/190b includes a portion of the interior
edges 78 such that, when assembled together, the pieces 190a/190b
define the complete perimeter of the elongated, arcuate opening 80,
which circumscribes the first fitting 54a similar to as shown in
FIG. 6.
For example, the pieces 190a/190b are initially separate and are
then assembled around the first fitting 54a and adhesively bonded
thereto to form the complete first shroud 158a. Thus, the shroud
158a can be fitted onto an existing vane as a retrofit, for
example. The use of the separate pieces 190a/190b also facilitates
removal of the shroud 158a for replacement with a new, similar
shroud, should the shroud 158a require replacement.
FIG. 10 shows a perspective, sectioned view through a portion of
the second fitting 54b. In this example, the second shroud 58b
further includes a seal member 90 attached at one of the perimeter
edges 76 of the second shroud 58b. The second fitting 54b, the
second shroud 58b and the seal member 90 are shown in full view in
FIG. 11. Similarly, as shown in FIG. 12, the first shroud 58a can
likewise include a seal member 90. When the vanes 32 are
circumferentially arranged in the gas turbine engine 20, the seal
members 90 bear against a neighboring shroud 58a/58b to provide a
gas path seal.
In the illustrated example, the seal member 90 is adhesively bonded
to the second shroud 58b using an adhesive 90a. Similar to the
adhesive 70, the adhesive 90a can be an epoxy adhesive.
Alternatively, the adhesive 90a can be another type of adhesive
that is suitable for the operating temperature of the airfoil. In
another alternative, the seal member 90 can be integrally formed
with the second shroud 58b, such as in a co-molding or over-molding
operation.
FIG. 13 shows a portion of a modified first shroud 258a. In this
example, the first shroud 258a includes a slot S extending into one
of the perimeter edges 76. The seal member 90 includes a flange 90'
that is received into the slot S to secure the seal member 90 and
the first shroud 258a together. The slot S can be sized in
correspondence with the size of the flange 90' such that there is
an interference fit or snap fit between the first shroud 258a and
the seal member 90. Alternatively, an adhesive can be used to
secure the seal member 90 within the slot S. Similarly, the second
shroud 58b can also include a slot for attaching the seal member
90.
Using the shrouds disclosed herein that are separate and distinct
pieces from the airfoil body 40 and the respective fittings 54a/54b
permits the shrouds to be made of different materials than either
the airfoil body 40 or the fittings 54a/54b. In one example, the
shrouds are, or include, a polymeric material. In a further
example, the polymeric material is a reinforced polymeric material
that includes glass fibers, carbon fibers, or other reinforcement
additives. In comparison to airfoils that are made entirely of
metal alloys, the airfoils disclosed herein provide a weight
reduction because of the use of the polymeric material.
Furthermore, metallic shrouds that are integrally formed with
fittings require significant raw material and machining to attain
the final geometric configuration. However, by forming the shrouds
disclosed herein from the polymeric material, the shrouds can be
formed to the required geometry and tolerances using known polymer
forming processes, such as injection molding.
FIG. 14 illustrates another example fitting 154b and shroud 158b.
In this example, the fitting 154b includes a body portion 92 that
receives a fastener 93 for securing the airfoil body 40 and the
fitting 154b together. The fitting 154b further includes a neck
portion 94 connected to the body portion 92, and a fillet portion
95 connected to the neck portion 94. The neck portion 94 includes a
shelf 94a that extends at the perimeter of the fitting 156b. In one
example, the shelf 94a is a continuous ring. The upper surface and
corner of the shelf 94a is complementary to the bottom inside
surface and edge of the shroud 158b such that the shroud 158b nests
into the shelf 94a. In one example, the shroud 158b is also a
continuous ring. An adhesive or mechanical fastener may be used to
secure the shelf 94a and shroud 158b together. The fillet portion
95 of the fitting 154b may form a smooth, flush surface with the
shroud 158b.
At its perimeter on one side, the shroud 158b includes a groove 97.
The groove 97 has a curved cross-sectional profile, such as a
partial- or semi-circle. A seal member 190 has a complementary
profile to the groove 97 and is received into the groove 97. An
adhesive may be used to secure the seal member 190 in the groove
97. The complementary shapes of the groove 97 and the seal member
190 facilitate proper seating of the seal element 190 in the groove
97.
Although a combination of features is shown in the illustrated
examples, not all of them need to be combined to realize the
benefits of various embodiments of this disclosure. In other words,
a system designed according to an embodiment of this disclosure
will not necessarily include all of the features shown in any one
of the Figures or all of the portions schematically shown in the
Figures. Moreover, selected features of one example embodiment may
be combined with selected features of other example
embodiments.
The preceding description is exemplary rather than limiting in
nature. Variations and modifications to the disclosed examples may
become apparent to those skilled in the art that do not necessarily
depart from the essence of this disclosure. The scope of legal
protection given to this disclosure can only be determined by
studying the following claims.
* * * * *